Tube bending machine



April 14, 1970 F.v sAssAK 3,565,852

TUBE BENDNGl MACHINE Filed March 7. 1968 4 Sheets-Sheet 1 April 14, 1970 F. sAssAK TUBEl BENDING MACHINE 4 Sheets-Sheet 2 Filed March 7. 1968 FIG. 4

FIGB

Il IIL.

INVENToR FRANK SASSAK l I 'l 36 IIN! ATTORNEYS April 14, 1970 F. sAssAK TUBE BENDING MACHINE 4 Sheets-Sheekl 3 Filed March '7. 1968 UNVENTOR FRANK SASSAK BYL'M,

WNWASI.

IIJU ATTORNEYS April 14, 1970 F. sAssAK 3,505,852

TUBE BENDING MACHINE Filed March 7. 1968 y 4 Sheets-Sheet 4 IHMI /7 F|G- l ,6

/5 92 'Ccearc l 93 95 m( INVENToR I 96 FRANK sAssAK /4J 75 BY M, MM, 5M

7 ATTORNEYS United States Patent O 3,505,852 TUBE BENDING MACHINE Frank Sassak, Dearborn, Mich., assignor to Bend-Rite, Incorporated, Detroit, Mich. Filed Mar. 7, 1968, Ser. No. 711,418 Int. Cl. B21d 7/024 U.S. Cl. 72-321 11 Claims ABSTRACT OF THE DISCLOSURE In a tube bending machine having a bed mounting a radius die, a die shoe mounting a rotative bending die and a power reciprocated ram; an improved lost motion actuator connecting means between said ram and die shoe for regulating reciprocal movements of said die shoe with respect to said bed; an improved support means for holding and guiding a tube to be bent for projection onto said radius die and to facilitate successive radial adjustments of the tube to produce a series of angularly related bends therein in a continuous operation, and an improved power operated tube clamping means for anchoring the tube during bending.

The present invention relates to the bending of tubes and more particularly to a tube bending machine which has a bed mounting a stationary radius die adapted to support a tube to be bent, together with a vertically adjustable die shoe which overlies and is guidably mounted upon said bed and mounts a rotative die for operative bending engagement with said tube in a mechanism substantially in accordance with the tube bending machine defined in my United States Patent 3,306,093, dated Feb. 28, 1967 and entitled Tube Bending Machine.

It is an object of the present invention to provide in conjunction with such machine an improved lost motion connecting means and actuating means which is interposed between the ram and the said die shoe by which reciprocal movements of the ram are transmitted into timed and successive reciprocal movement of the die shoe and the connected bending die Iby which a series of successive similar or angularly related bends may be formed in a tube in a continuous bending operation.

It is another object of this invention to provide an improved tube supporting and guiding means on the bed of the tube bending machine, adapted to retain and guidably direct the tube to be bent to and onto the radius die and to provide a means by which the tube may be mounted in one or a plurality of successively different angularly related positions for achieving a series of angularly related bends successively throughout and upon the length of the said tube to be bent.

It is another object of this invention to provide an improved power operated clamping means upon the bed which overlies the tube when nested upon the radius die for anchoring the same during tube bending in a releasable manner by which after bending the tube may be angularly oriented radially to provide a successive bend in the tube at an angle to the first bend and which wherein such angular adjustment may be at any angle throughout 360 to thus produce in the finally bent tube a series of angularly related bends.

These and other objects will be seen from the following specifications and claims in conjunction with the appended drawings, in which:

FIG. 1 is a fragmentary front elevational view of the present tube bending machine.

FIG. 2 is a fragmentary perspective View thereof.

FIG. 3 is an enlarged front elevational view of the lost motion connector actuator for the machine die shoe.

rice

FIG. 4 is a fragmentary and partially sectioned side elevational view thereof.

FIG. 5 is a fragmentary front elevational view of the tube bending machine showing the construction of the tube support means with the die shoe retracted.

FIG. 6 is a similar view showing the die shoe moved through and to tube bending position.

FIG. 7 is a fragmentary section on an enlarged scale taken in the direction of arrows 7-7 of FIG. 5.

FIG. 8 is a fragmentary elevational section on an increased scale of a portion of the tube support mechanism.

FIG. 9 is a fragmentary section taken in the direction of arrows 9 9 of FIG. 5.

FIG. l0 is a similar view taken in the direction of arrows 10-10 of FIG. 6.

FIG. 11 is a fragmentary and schematic View of the power train for the tulbe bending machine.

It will be understood that the above drawings illustrate merely a preferred embodiment of the invention, and that other embodiments are contemplated within the scope of the claims hereafter set forth.

Referring to the drawings, the present tube bending machine is incorporated into a conventional type of press which is fragmentarily shown in FIGS. l and 2, the bending machine being generally designated at 11 as including a base 12, a column 13, a power reciprocated ram 14, a conventional motor driven pulley wheel 15 fragmentarily shown connected with a suitable motor mounted upon the column as schematically illustrated in FIG. 11.

Wheel 15 through shaft 16 drives pinion 17 in turn in driving engagement with gear Wheel 18 which through a manually operable clutch 92, which could be foot pedal operated in a conventional manner, controls rotation of the eccentric 93 for effecting reciprocal movements of the ram 14 in a conventional manner, one support bearing for the eccentric 93 being designated at 94, said eccentric also mounting the control cam 95, FIG. 11.

This portion of the described machine is reasonably conventional in presses.

LOST MOTION CONNECTOR-ACTUATOR FOR DIE SHOE The present tube bending machine includes the bed 40 fixed to the base 12 and which is adapted to mount and support the radius die 48 channeled at 49 to receive and support thev tube TI during bending. The present tube bending machine also includes an elongated die shoe 36 which is reciprocally mounted upon and movable relatively to bed 40 and is adapted to mount the rotative tube bending assembly, which includes rotatable bending die 43, pinion 44, reciprocal rack 45 connected to a reciprocal piston 46, FIG. 5, movaible within cylinder 47 to which pressure is applied "to oppose the rotative tube bending movements substantially as disclosed in United States Patent 3,306,093, referred to above.

The present improvement is directed to the lost motion actuator connecting means between the conventional reciprocated ram 14 and the said die shoe 36.

This connecting means includes mounting plate 19, FIGS. 3 and 4, secured to ram 14 by fasteners 20. Spaced forwardly thereof is front plate 21 with the guideways and spacers 22 interposed between plates 19 and 21 to dene an elongated housing thus mounted upon ram 14 for reciprocal movements therewith.

A polygonal cam block 23 having a series of angularly related surfaces is interposed between the housing plates 19 and 21 and rotatively supported thereon by its respective axial Shanks 24 and 25 nested within the respective plates 1-9 and 21 and adapted for securing in any desired position of angular adjustment by set screw Z7.

The shank terminates in the axially outwardly extending spindle 26 which extends through cover plate 28 and with the assembly completed and secured together by a series of fasteners 29 which completes the box construction and anchors the guide plates 22 therein.

The present actuator-connector 30 is guidably and movably mounted within said housing in registry with the guideways 22 and is adapted for reciprocal movements relatively to the housing. Such relative reciprocal movements ibetween the actuator-connector 30 and said housing are limited by the pin and slot connection which includes stop pin 31 which projects forwardly of actuator-connector 30 and extends through corresponding slots 32 formed in plates 21 and 28 as best shown in FIG. 3.

The lower end portion of actuator 30 projects 'below said housing and is notched or cut away at 34 to receive lthe upright mounting boss 35 which is anchored as by welding to the die shoe 36, fragmentarily shown in FIGS. 3 and 4, employing a series of fasteners 37.

Upright longitudinally spaced guide sleeves 38 depend from die shoe 36 and are movably and guidably mounted over the guide posts 39 which are secured to and project from end portions of bed 40 for guiding reciprocal movement of die shoe 36 relative to bed 40 and for maintaining proper registry therewith and between radius die 48 and the bending die assembly 42-43.

'Ihe undersurface of the rotatable bending die 43 has a longitudinal channel or groove for operative registry with the portion of the tube T to be bent during downward movement of the die shoe 36 under the control of the ram 14 and the connector-actuator 30.

Due to the construction of the bending assembly 42 and wherein the path of longitudinal movement of the rotatable die 43 is displaced from the center of the stationary radius die, during the 'bending operation the rotative die 43 in FIGS. 2 and 5, rotates to the relative position shown in FIG. 6, in a manner and by the structure specifically defined in my United States Patent 3,306,093, which construction is not repeated herein.

The present radius die 48 includes the semi-circular groove or corresponding channel 49 of the correct radius in order to cooperatively receive the tube T during the tube bending operation, said radius die being secured as by fasteners 50 to the bed 40.

TUBE SUPPORT MEANS In accordance with the present invention an improved means is provided for supporting the tube T prior to and during a series of successive bending operations and by which the tube is directed onto the radius die 48 at the correct attitude or angle for a particular bending operation.

This tube support meansincludes the elongated bed extension 51 aihxed to bed; 40, and extending laterally thereof, including dovetailguideway 52, FIGS. 6 and 7, adapted to register with the correspondingly shaped dovetail slots 54 on the series of longitudinally spaced and adjustable support plates 53. Each support plate includes a irst aperture 55 terminating in split portion 56 communicating with its dove tail slot 54 to provide a means of frictionally securing by fasteners 57 the said support plates 53 adjustably upon guideway 52.

Additionally aperture is provided within the plates 53 aligned with apertures 55 within which is nested a preferably hardened bushing or sleeve `58 including an annular flange at one end in registry with the respective plates 53. The bushing or sleeve 58 is secured in position by the set screw 59, FIGS. 6 and 7, and are adapted to rotatively support the elongated guide tube l60 adapted to supportably receive the tube T to be bent. Guide tube 60- at one end includes the tapered split collet 61 of reduced diameter adapted to frictionally engage the tube T for retaining the same with respect to the guide 60 and by which the said tube is frictionally anchored and centered for direction onto the radius die 48.

Referring to FIG. 8, detent 62 is pivotally mounted at `63 within the slot in the side wall of the guide 60 and is normally biased outwardly of the tubular support 60 iby the leaf spring 64 anchored at 65 within the tubular guide 60.

Within at least one of the annular flanges of the bushings 58 there is provided a radial slot 66 which extends into the bore of the tubular support 60, and with the tube T assembled Within the tubular support 60, retainingly receives detent 62 for anchoring the tubular guide 60 with respect to flange bushing 58 upon one of the Support plates 53.

Thus, the bushings 58 may be rotatably adjusted at any desired angle throughout 360 and anchored within the support as by fastener 59 to thus locate radial slot 66 at a predetermined angle and the tube T at a corresponding relative angle since said tube is frictionally retained within guide 60 by the split collet 61.

This may provide an initial reference location for the tube 60 for a primary or secondary successive bending operation of the tube T from which one or more or a series of angularly related Successive bends may be made in the tube starting from a reference point determined by the original location of slot 66 in bushing 58, said tube adapted for longitudinal and rotative adjustment successively through said bushings.

POWER OPERATED TUBE CLAMPING MEANS Referring to FIGS. 5, 6, 9 and l0, clamping arm 71 is oif center and intermediate its ends pivotally mounted at 69 upon block 70 on bed 40 with the pivot axis parallel to the longitudinal axis of the tube support 60 and being off center normally assumes the release position shown in FIG. 9. Transversely arranged tube clamping bar -67 is mounted upon one end of the clamp arm 71 and includes an elongated channel or groove 468 adapted for cooperative retaining registry with the tube T within the radial die 48 for securing the same during the tube bending operation, FIG. 6.

The opposite end of arm 71 is slotted at 72 to loosely receive cam wheel 73 which is adapted for vertical adjustments within the said slot 72 under the control of the cam 74 upon one end of the piston rod 75 of the pneumatic cylinder or motor 76 which is anchored at 77 upon bed 40 as best shown in FIG. 2.

Conduits 78 and 79 fragmentarily shown in FIG. 2 are adapted to receive and to exhaust pressure uid such as compressed air under the control of the valve 98 shown in FIG. 1l, said valve, a conventional two-way valve, whose operation is controlled by a cam on the ram driving eccentric 93, FIG. 11. By this construction, upon rotation of eccentric 93 causing intermittent downward movements of the ram 14 and corresponding movements of the bending mechanism, such downward movement of the ram provides a corresponding operation of `valve 98 controlling the pneumatic cylinder 76 by which the clamping mechanism is actuated and the workpiece clamping bar 67 is projected operatively against the tube T during the bending operation such as is shown in FIGS. 6 and 10. 0n reverse of the ilow of pressure fluid or compressed air or its release to the atmosphere the clamping arm 71, FIG. 10, will return by gravity to the position shown in FIG. 9 releasing the tube after the bending operation.

Such tube release is accompanied by and caused by the upward return movement of the ram 14 in an assembly such as shown schematically in FIG. 11. Accordingly, as the ram 14 retracts following the bending operation, the tube is released with respect to the radius die 48 and can be advanced longitudinally for an additional bending movement which would, if continued repeatedly, produce a coil such as shown in FIG. 2 or which by rotation of the tube radially upon rotation of the tube guide 60 produce a plurality of angularly related bends within the tube such as shown in FIG. l.

INDEXING MECHANISM FOR ACTUATOR- CONNECTOR In operation of the present bending machine wherein the ram transmits through lost motion reciprocal movements to the die shoe 36 the mechanism of the actuatorconnector shown in FIGS. 3 and 4 is employed. Here it is noted that initial downward movement of the ram effects the corresponding downward movement of the housing 19-22-21-28 which loosely and guidably mounts the actuator-connector 30. Such downward movement causes a corresponding downward movement of the polygonal cam 23 until one of its at surfaces normally spaced from the end of the actuator-connector 30 operatively engages said actuator-connector at its upper cam end 41. Continued downward movement of the ram and associate housing thus causes downward movement of the actuator-connector 30 and a corresponding downward movement of the die shoe 36 connected thereto, FIGS. 3 and 4.

After the bending operation as the ram 14 begins to retract causing an upward retracting movement of the housing 19-21 due to the -lost motion pin and slot connection 31-32, the actuator-connector 30 does not retract until bottom portion of the slot 32 of the housing comes into operative engagement with the pin 31; thus on continued upward movement of the ram lifts the actuator 30 and accordingly lifts the die shoe 36, retracting the bending mechanism.

As shown in FIG. 4, upon each of the flat surfaces of the cam block 23 there are provided threaded apertures 98 adapted to receive suitable fasteners for anchoring to the said corresponding at surface, a shim or spacer 91 such as shown in FIG. 3. Accordingly, when the spacer or block 91 has been indexed so as to project downwardly for operative registry with the cam end 41 of the actuator 30, it lbecomes clear that the said cam block 23 will engage the actuator 30 sooner and thus provide a means for modifying the extent of downward bending movement of the die shoe.

In .accordance with the present invention, a power operated means is provided for indexing the cam block 23 so that the extent of a particular bend may be controlled automatically by effecting a predetermined rotation of the cam block 23. For this purpose there is provided upon the spindle 26 which projects axially from the cam block 23 upon the exterior of said housing, a suitable ratchet wheel 83 secured as at 84 to said spindle. Pivotal index plate 80 at one end is pivotally mounted upon and with respect to the spindle 26 FIG. 4, and mounts pawl housing 81 for the reciprocal spring biased pawl 82 adapted for intermittent operative engagement with the ratchet 83 upon pivotal movement of the index plate 80 in a counterclockwise direction. In the present embodiment of the invention, successive pivotal movements of the ratchet are achieved by and through the power cylinder 85 which is pivotally mounted at one end at 86 upon housing plate 21 and has projected axially from its opposite end, the piston rod 87 which is pivotally connected as at 88 to a portion of the index plate 80 for controlling pivotal movements thereof to the extent of which is limited by the stop 96 on stop plate 97 suitably anchored to cover plate 28 of said housing. Air lines 89 and 90 are connected as shown fragmentarily to opposite ends of the cylinder 85 and are under the control of a suitable valve, the same as or similar to valve 98 for controlling activation of the piston rod 87 as desired by the operator for effecting indexing rotative movements of the cam block 23 for determining indexing said block setting the extent of bending movement of the die shoe 36. Normally there would be a separate manual control for a suitable valve regulating the ow of compressed air to the respective opposite ends of cylinder 85 through conduit 89 or 90 for regulating said indexing movements.

Having described my invention, reference should now be had to the following claims.

I claim:

1. In a tube bending machine having a bed mounting a stationary radius die adapted to support a tube to be bent, a vertically adjustable die shoe overlying and guidably mounted upon said bed and mounting a rotative die for operative bending engagement with said tube, and a power operated reciprocal ram;

the improvement comprising a lost motion connecting means between said ram and die shoe; a laterally extending tube support means on said bed for guidably directing said tube onto said radius die;

and a power operated clamping means on said bed for anchoring said tube upon said radius die during tube bending.

2. In the tube bending machine of claim 1, said lost motion connecting means in-cluding an elongated housing, mounted on said ram overlying and spaced from said die shoe;

an elongated connector-actuator losely and guidably mounted reciprocally within said housing and at one end projecting therefrom and secured to said die shoe;

a pin and slot connection between said actuator and housing;

and an adjustable cam stop adjacent an upper portion of said housing spaced from the other end of said actuator, and upon downward movement of said ram and housing, operatively engageable with said connector-actuator effecting successive downward movement of said rotative die;

said pin and slot connection providing sucessive delayed return movement of said die shoe upon upward movement of said ram.

3. In the tube bending machine of claim 2, said stop including a polygonal block with its outer surfaces at different center distances from its axis;

and axial Shanks projecting from its opposite ends journaled within said housing;

said block being adjusted so as to provide a downwardly facing surface opposed from said actuatorconnector.

4. In the tube bending machine of claim 3, a ratchet fixed on one block shank on the exterior of said housing;

a power actuated reciprocal plate pivoted upon said latter shank mounting a spring biased pawl oper- .atively engageable with said ratchet for selectively rotating said cam stop to vary the downward feed movement of said die shoe.

5. In the tube bending machine of claim 1, said tube support means including a plurality of upright longitudinally spaced plates with aligned apertures therethrough;

an elongated tubular guide extending rotatably through said openings, with its axis in alignment with the radius die;

and a tapered split collet on one end of said guide adjacent said radius die adapted to frictionally grip the tube to be bent.

6. In the tube bending machine of claim 5, a bushing in the aperture of each support plate, receiving said tubular guide;

each bushing including an annular flange at one end engaging a support plate;

and friction means anchoring said bushings in said support plates respectively.

7. In the tube bending machine of claim 5, a bushing in the aperture of each support plate receiving sad tubular guide;

at least one of said bushings having an annular flange at one end engaging its support plate;

friction means anchoring said flange bushing in said support plate;

said flange having a radial slot;

and a spring biased detent pivoted upon said guide tube and retainingly projected into said slot, said flanged bushing -being rotatively adjustable for setting said slot at any predetermined angle throughout 360.

7 Y 8. In the tube bending machine of claim 5, Vsaid bed including an elongated dovetail guideway aligned with said radius die;

said support plates having similar dovetail slots for sliding adjustment registry upon said guideway;

and friction means on said support plates for locking them in longitudinally adjusted position.

9. In the tube bending machine of claim 1, said power operated clamping means including a clamping bar pivotally mounted upon bed, off Center, and upon an axis parallel to the tube support means;

a transverse elongated clamping block upon one end of said bar, having an undercut channel to operatively receive the tube to-be bent for clamping the same relative to said radius die during bending;

said bar normally biased to tube release position;

and power means on said bed operatively engageable with said clamping bar adjacent its other end for pivoting the same into tube securing position.

10. In the tube bending machine of claim 9, said power means including a motor on said bed having a reciprocal piston rod;

a cam on said piston rod;

and a cam responsive movable means on said clamping bar.

11. In the tube bending machine of claim 10, a control valve to regulate said motor and reciprocal movements of said piston rod;

a source of compressed air connected to said valve for selective delivery to the respective opposite ends of said motor;

and cam means on said bed connected to said ram for activating said valve and said motor operated workpiece clamping means upon each downward feed movement of said ram and for automatic release movement on retraction thereof.

References Cited UNITED STATES PATENTS 3,217,524 ll/1965 Stanley 72--159 X 3,306,093 2/1967 Sassak 72-389 2o MILTON s. MEHR, Primary Examiner U.S. Cl. X.R. 72-322, 386 

